Here we are at the end of the Northern Hemisphere harvest season, but that doesn't mean you have to pack up your tools and stare wistfully out the window at your garden for the next few months. With a little preparation now and the right choice of plants, you can have some fresh produce on hand throughout winter and get a head start on your early spring crops.
In order to have springtime success with fall-planted and overwintered vegetables, it’s important to know the growing zone you live in: that’s going to have a big impact on what you can and cannot grow. For example, I’m in Montreal, which is zone 5, borderline 6, and planting anything outdoors for harvesting during winter is out of the question for me. Ditto trying to overwinter broccoli, since I don’t have a heated greenhouse in my backyard. But even here, believe it or not, there are things that I can sow or plant now that will ensure I am the first kid on the block with a serving of homegrown produce come spring. For growing zone guides worldwide, you can find comprehensive maps here, and the detailed USDA map can be found here.
In milder zones, you’ll be able to grow most of the traditional overwintering crops such as root vegetables and brassicas. In fact, if you’re in Florida, winter is the only time you’re likely to have much success with these crops. As you head further north or into higher altitudes, cold frames and poly tents become the winter gardener’s ally, helping you to nurture plants through until the days start getting longer and the plants start to regain their vigor and reward you with your first spring vegetables. Well-composted raised garden beds are also recommended, as they improve drainage in wet winter weather thereby reducing the chance of rot. A protective layer of mulch is the plant’s equivalent of a granny’s knee rug when it comes to insulating your leafy charges too. As you get further north still, well, even here in freezing eastern Canada I manage to molly-coddle along basil, chili pepper, oregano, chives, and the like by keeping them inside next to a south-facing window over winter.
If you can’t grow vegetables outdoors during winter because it’s too cold, you can still pre-seed your garden for early spring germination. Pre-seeding your veggie patch lets nature decide for herself when the time is right for your spring seedlings to sprout. Plant the seed of spring-growing vegetables once it’s too cold for them to germinate, then mulch and wait. Continually frozen soil over winter is better for the seeds than a cycle of freezing and defrosting. The temperature dropped to -27C (-17F) here last winter and I still had self-seeded lettuces, wild arugula, and shiso plants pop up in the planter boxes in May. Pre-seeding does require a tolerance to some loss though, especially if you live in a high rainfall area where seed may rot. Spread more seed than you think you might need because you can always transplant or give away extras in spring if you are too successful. Ideal pre-seeded crops include arugula (rocket), lettuce, brassicas, radish, and basil, as well as the usual compost heap volunteers, cherry tomatoes and pumpkins. While you’re busy throwing seeds about, don’t forget your summertime pollinator friends either: be sure to add some milkweed and local wildflower seeds into the mix so bees and butterflies have something to forage on as soon as possible too.
Below you’ll find a list of some familiar – and not so familiar – cool weather crops that you can plant out as seeds or bulbs now for an early spring harvest, climate zone permitting.
Fall-planted leafy greens such as kale and collards are not only tough enough to survive the cold – and even snow – they usually taste all the better for it. The added beauty of growing these vegetables over winter is that they are cut-and-come-again crops. You can lightly harvest what you need for mid-winter meals, and they’ll still be ready to leap into action once the days start getting longer. This gives you a constant supply as you transition into spring, instead of making you wait all winter long for a single vegetable to mature. There are many varieties of kale and collards, so consult local resources for the best varieties for your climate zone and prepare yourself to be overwhelmed by choice. My favorite kale is the Cavolo nero, or Tuscan kale, but you can even eat the quite common ornamental kale at a pinch if you still have some hanging around by spring – though it’s not the tastiest or most tender variety. Spinach can also be overwintered for a first spring crop; however, it’s not quite as tough as kale and collards. Be sure to mulch it well and put it under glass if you are in a frost-prone area.
If you have the space, winter onion varieties can be a set-and-forget crop. Give them plenty of food, weed-suppressing mulch and good drainage, keep a eye out for pests such as slugs, and you should be right. The big catch is they won’t be ready to harvest until summer. For an earlier crop, try some of the smaller alliums. Shallots will grow wherever onions thrive and add a delicate taste to dishes that is especially prized in French cuisine. Shallots are a clumping allium, and it’s recommended to retain the biggest shallot from each clump for replanting the following year. Scallions (or green onions or spring onions) for spring harvest can be slipped in just about anywhere in the garden, as long as it’s a sunny spot. Another excellent overwintering allium is the Egyptian onion, or tree onion. Instead of a flower head, these plants produce a cluster of baby onions at the top of their leaf spike, which eventually becomes so heavy it droops over, hits the ground and takes root. As a perennial, these are an excellent choice for home gardens, giving you tasty little onions for pickling, salads and cooking. While the “topsets” are mature in late summer, you can eat the green shoots, immature young onions and older, overwintered onions before then. Unfortunately, Egyptian onions don’t produce in their first year of growth, so you have to demonstrate a little gardeners’ patience. (Sigh!) Egyptian onions have been known to survive -24F, can tolerate being buried by snow and will grow well in zones 3 to 9.
Garlic is an allium too, but it deserves its own special mention. Fall is the time to plant garlic, though it won’t be ready to harvest as a mature vegetable until next summer. In spring, however, you can treat yourself to green garlic shoots, and if you plant “hardneck” garlic varieties, you can harvest garlic scapes in May to early summer. When planting garlic, bury each clove about three inches deep, cover with soil and mulch well. This is one crop that’s definitely worth the effort for the difference in taste between the homegrown organic version and its well-traveled imported cousin. It can also be squeezed in just about anywhere, and will happily grow in a tub.
Peas and broad beans
In milder climate zones you can plant peas and broad beans in fall for an early spring harvest. A fall planting can produce pods up to a month earlier than a spring planting, and you can also pick the shoots and leaf tips for inclusion in salads, sautés and stir fries. Provided your soil doesn’t get too wet and waterlogged, you can also try pre-seeding them if you live in a zone that’s too cold for outdoor winter growing – there’s only really one way to find out if that’s going to work for you, right? To increase your harvest length, plant both early and late harvest varieties of peas and broad beans, and if you have the space, include snow peas (mangetout) and edamame. I had great cool-climate growing success with edamame last spring and early summer, so I’m going to try pre-seeding them this fall.
Broccoli and cauliflower
These hardy favorites always pop up on mid- to warmer-zone winter growing lists, but I’ll make a confession: I’ve never once had success with homegrown cauliflower in over 20 years of gardening across a multitude of climates. If you’ve got a hot tip for homegrown cauliflower success, please feel free to share in the comments. However, if you are just starting out with a veggie patch, it might be best to give the single-harvest caulis a skip for now and try some sprouting broccoli. Like the leafy greens, this crop is cut-and-come-again, making it ideal for home gardens as you’ll get a light to regular supply all winter long, depending on your location. Overwintered sprouting broccoli will then really start to flourish come spring. If you find your brassicas seem to stall as the weather cools down, just give them some more mulch and when the weather warms up they’ll take off again to give you an early spring crop.
If kept protected from the extremes of winter, fall-planted cabbages will chug along slowly over the colder months and give you a head start on a spring crop. Because cabbages are a single-harvest vegetable, ensure you don’t wind up with 20 of them maturing all at once in spring by planting a mixture of red, green and Savoy cabbages. Look out for shorter and longer growing season varieties too and you will be able to stagger your spring harvest. Cabbages are heavy feeders, so prepare their beds well, and be sure to practice crop rotation to lower the risk of disease being passed on from one year’s crop to the next.
Like the leafy greens, root vegetables are often all the sweeter for being overwintered, and parsnips especially benefit from taking a hit of frost. Options here include carrots, parsnips, beetroot, swedes (rutabagas), turnips and salsify. If you are lucky enough to not get frosts, the larger daikon radish is a possibility as well. While daikon loves a cool climate, it is not so fond of frost, but cold frames can give you a bit of grace here too. In spring, be sure to start harvesting if your beets or carrots show hints that they are sending up flower heads. The vegetables will become bitter if left to flower. If the ground gets just too cold to leave root crops in the soil where you are, pull up as late a harvest as you dare, don’t wash the vegetables but do trim off their leaves, and store them in clean sand in a frost-free space such as a mud room or basement. This effectively puts the vegetables into suspended animation. They’ll stay nice and plump instead of drying out or going all wrinkly and limp like they would in the fridge.
Unless you are in a warm hardiness zone, bring your potted herbs inside and pop them in a sunny spot over winter. With enough light, woody perennials such as thyme, sage and oregano should soldier on through, though rosemary can be temperamental about water and humidity, so maybe don’t get too attached to outcomes there. That said, some herbs we normally consider annuals can actually be grown perennially, or at least biennially. Parsley is a useful and long-lasting cooking and salad herb that will overwinter well indoors with adequate light and watering. As I type, I have a chili plant to my left and a basil plant to my right: both are 15 months old and are showing no sign of quitting any time soon. Friends here in Montreal have basil plants that are heading into their fourth winter, and while you won’t be making huge batches of pesto in March, keeping potted basil indoors over winter will ensure you have enough to toss through pasta or salads in early spring.
Arugula (or rocket) is hands down my favorite homegrown vegetable: it lives up to the rocket moniker with super fast germination, and you will be picking baby leaves within 30 days of planting seeds. A fall planting under cold frames or in a pot indoors should get you through to spring, but be sure to pre-seed some in a sunny spot so your spring crop starts as soon as the weather allows. Even if you’re not overly fond of arugula’s peppery taste, its vigor will keep you motivated to tend to your other plants as the mercury drops. If you do like strongly flavored salad leaves, plant some frost-tolerant radicchio and endive as well. Both of these come in several varieties and will add color, texture and a pleasant hint of bitterness to your winter and early spring salads. Young radicchio can be picked as a cut-and-come-again crop and endives can be “blanched” while still in the ground to reduce their bitterness. Radicchio can also be grilled once it has formed a head, and both endive and radicchio can be baked, which sweetens them a little. Some of the hardier lettuces, such as cos, can be nurtured in cold frames over winter, though if you have room indoors you could also grow a potful of mixed mesclun leaves in a sunny spot to have baby salad greens all winter long that can then be moved out of doors as it gets warmer.
Asparagus and artichokes
If you have the space, the right climate zoning and you are confident you are going to have access to your current garden for a few years to come, please consider planting some of these perennials. You will be rewarded with vegetable luxury every year come early spring. The catches? Colder than zone 8 and artichokes should really be grown as an annual, which means they won’t be ready for a spring harvest. However, asparagus can be grown in zones 4 to 9, which makes it quite versatile as a first-of-the-season crop. Florida is generally too warm for either of these beauties to grow with much success. Asparagus can take up to three years to get going, especially if started from seed, but it will reward you with up to 25 years of crops. That’s quite a payoff, and the al dente give of a lightly cooked, new season’s spear of homegrown asparagus will rapidly make the trials of winter seem like they happened months ago.
Photos: Lead image by Robert S. Donovan, kale by Noelle, sprouting broccoli by Korye Logan, Egyptian onions by Eunice, garlic by Oisin Hurley, carrot by Brett Forsyth, broad beans by Glenn, cabbage by Kurt Bauschardt, radicchio by Eunice, herb pot by nociveglia, artichokes by Jewel o’ the desert via Flickr.